Nut and tail assemblies are typically moulded from plastics material, the typical assembly including a tail having an external thread at one end and an outstanding flange or lip at the other end with a stem extending therein between, said assembly also including a nut having an inturned flange that bears against the back of the tail outstanding flange and is arranged to firmly retain the assembly to a male threaded fitting. These fittings can be made many ways such as spin-welding or two-part operations. Other conduit fittings such as barrel unions, and fittings on the ends of valves can be made by the same methods.
In a previous patent by the same applicant, Australian Patent 579,134, whose contents are expressly incorporated by reference herein, there was disclosed both a method and a fitting manufactured by said method that greatly simplified the construction of such a fitting having a nut and tail of moulded plastics material. The method included placing the nut in a die and moulding the tail with the nut in one single die operation so that the tail outstanding flange was moulded within the body of the nut, the nut inturned flange located behind the outstanding flange of the tail. Such a method and fitting greatly simplified the then known manufacturing processes.
Although the fitting as described in the aforementioned patent has been found to work satisfactory in most circumstances it has been found that lateral twisting and bending of such a fitting can cause failure in the fitting especially in the body of the tail or stem immediately adjacent the inturned flange of the nut. In situations where such a fitting may be prone to lateral forces this type of fitting is therefore unsuitable.
It is an object of the present invention to propose improvements in such a fitting and construction thereof whereby there is proposed a fitting having a nut, a tail of moulded plastics material, a sleeve extending at least partially over said tail and formed of a resilient material.
It is a further object of the preset invention to provide for improvements in the construction of such a fitting or at least provide the public with a useful alternative.